FIG. 8A is a top view showing a conventional vehicle lamp 100 (those other than major optical surfaces are omitted); FIG. 8B is a cross-sectional view taken along line A-A in FIG. 8A (those other than the major optical surfaces are omitted); and FIG. 8C is a cross-sectional view taken along line B-B in FIG. 8A (those other than the major optical surfaces are omitted).
As shown in FIG. 8A, there has been conventionally known the vehicle lamp 100 (see FIG. 32, etc. of Patent Literature 1, for example) including: a front lens body 101; a rear lens unit 102 disposed behind the front lens body 101; and a light source 103 that is disposed behind the rear lens unit 102 and emits light to be irradiated forward after passing through the rear lens unit 102 and the front lens body 101 in this order so as to form a low-beam light distribution pattern (see FIG. 9). The rear lens unit 102 is a lens unit that serves to condense light in a first direction (e.g., an up-and-down direction in FIG. 8A), and the front lens body 101 is a lens unit that serves to condense light in a second direction orthogonal to the first direction (e.g., a direction orthogonal to the plane of the paper in FIG. 8A).
The rear lens unit 102 includes: a first light-entering surface 102a; a first light-exiting surface 102b opposite to the first light-entering surface 102a; an edge section 102c provided between the first light-entering surface 102a and the first light-exiting surface 102b (focal point F); and a reflection surface 102d extending rearward from the edge section 102c. 
The edge section 102c includes: a first edge part e1a corresponding to a left cutoff line CL1a; a second edge part e2a corresponding to a right cutoff line CL2a; and a third edge part e3a corresponding to an oblique cutoff line CL3a connecting between the left cutoff line CL1a and the right cutoff line CL2a. 
The reflection surface 102d includes: a first reflection surface r1a including the first edge part e1a; a second reflection surface r2a including the second edge part e2a; and a third reflection surface r3a including the third edge part e3a. 
The third reflection surface r3a extends rearward from the third edge part e3a along a reference axis AXLo extending in a vehicle longitudinal direction. That is, the third reflection surface r3a is a surface parallel to the reference axis AXLo.
The front lens body 101 includes: a second light-entering surface 101a; and a second light-exiting surface 101b opposite to the second light-entering surface 101a. 
When the light source 103 is turned on in the vehicle lamp 100 with the above-described configuration, light from the light source 103 enters the rear lens unit 102 through the first light-entering surface 102a, and exits, after being partially blocked by the reflection surface 102d, through the first light-exiting surface 102b together with reflected light from the reflection surface 102d. Then, the light from the light source 103 that exits through the first light-exiting surface 102b is condensed in the first direction due to the function of the first light-exiting surface 102b. The light from the light source 103 that has exited through the first light-exiting surface 102b then passes through a space Sa between the rear lens unit 102 and the front lens body 101, further enters the front lens body 101 through the second light-entering surface 101a, and exits through the second light-exiting surface 101b to be irradiated forward. Then, the light from the light source 103 that exits through the second light-exiting surface 101b is condensed in the second direction due to the function of the second light-exiting surface 101b. This forms the low-beam light distribution pattern.
Patent Literature 1: WO2015/178155